1. Field of the Invention
This invention relates to a new class of copolymers and more specifically to copolymers of cyclopropenes and unsaturated or strained ring comonomers or mixtures of unsaturated and/or strained ring comonomers that undergo addition polymerization in the presence of free-radical or coordination-type initiators.
2. Description of the Prior Art
The following references are of interest in connection with the present invention:
1. K. B. Wiberg and W. J. Bartley, J. Am. Chem. Soc., 82, 6375-80 (1960), which describes the "spontaneous" polymerization of cyclopropene to a polymer (no physical description) characterized by the absence of resonance in the vinyl and aliphatic CH.sub.2 region and by a broad band in the region .tau. = 9.7- 9.8 (cyclopropane) as having the structure: ##SPC1##
2. F. Fisher and D. E. Applequist, J. Org. Chem., 30, 2089 (1965), which indicates decomposition of 1-methyl cyclopropene ("probably polymerization") to a substance to which no structure is assigned.
3. G. L. Closs and L. E. Closs, J. Am. Chem. Soc., 85, 99-104 (p. 102) (1963), which mentions the ready polymerization of impure ##SPC2##
4. S. Murachashi, S. Nozakure, and M. Furne, Kobunshi Kagakn, 23 (255) 543 (1966), C.A. 67, 2131 (1967), which reports polymerization of cyclopropanes. With chloro substituted cyclopropane, dehydrochlorination was observed yielding polymers having cyclopropane rings in the main chain.
5. C. S. Marvel, J. H. Sample and Max F. Roy, J. Am. Chem. Soc., 61, 3241 (1939), which reports that the dehalogenation of polyvinyl chloride (and bromide) with zinc removed 84-87% of the Cl (85.9% of Br) to yield a soluble polymer which did not react with permanganate and was assigned the structure ##EQU1##
6. J. K. Hecht, Polymer Letters, 6, 395-401 (June, 1968), which reports that tetrachlorocyclopropene was copolymerized under free-radical conditions with styrene and vinyl acetate to give structures of the formula ##EQU2## wherein R is --C.sub.6 H.sub.5 or --OCOCH.sub.3 . Tetrachlorocyclopropene reportedly copolymerized poorly with acrylonitrile and not at all with methyl methacrylate.
7. M. Yamabe, Asahi Garasu Kenkyu Hokoku, 17 (2), 109-117 (1967) (translation): Polymerization of 1-Methylcyclopropene, shows homopolymerization of 1-methylcyclopropene in the presence of a coordination catalyst which promotes both double bond polymerization and ring-opening polymerization to yield a random copolymer containing the unit ##EQU3## and ##EQU4##
On the other hand, in the copolymers of the present invention, there is no double bond in the noncyclic repeating unit which forms part of the main chain of the copolymer.
8. Gale et al, J. Am. Chem. Soc. 88, 3617-23 (1966 ) shows the reaction ##EQU5## No disclosure appears to be present as to the polymerizability of the reaction product.
9. Barkdoll and Sargeant, U.S. Pat. No. 3,413,275 (1968) shows copolymerization of halotrifluorocyclopropenes of the formula ##EQU6## where X is fluorine, chlorine or bromine, with ethylenically unsaturated monomers.